Kate Middleton on Thursday posted a personal message ahead of Together at Christmas Carol Service.
Taking to Instagram, the Princes of Wales also shared glimpses of a letter which she said "will be shared with every guest at the Together at Christmas Carol Service at Westminster Abbey tomorrow night as well as at the Community Carol Services nationwide."
A caption accompanying the letter's photos read, "A message of gratitude and hope - reflecting on the power of love, empathy, and the strength we find in one another."
The pictures shared on Instagram show the letter starting with 'Dear Guest' and ending with Kate's signature, 'Catherine'.
Actors Kate Winslet, Hannah Waddingham and Chiwetel Ejiofor will be among the stars joining the British royals for the annual Christmas carol service hosted by Kate.
The 'Together At Christmas' service, which will be held on Friday and is the fifth such event that Kate has spearheaded, heralds individuals across the country who have given their time to help others, and brings people together to "celebrate love in all its forms", Kensington Palace said.
Some 1,600 people who have supported people in their communities will join the royals, while the Abbey's choir will perform carols and there will also be performances by the likes of Waddingham and singer Katie Melua.
Kate's husband, Prince William, will be among those who deliver readings.
The event will be broadcast on Britain's ITV on Christmas Eve, while 15 community carol services supported by the couple's Royal Foundation charitable arm will also be held across Britain during December.
